Taiwanese Patent No. 1513955 discloses a conventional thread measuring tool used for checking a female threaded member, such as a nut. As shown in FIG. 1, the thread measuring tool is a rotating shaft 8 with a male threaded end segment 7. The male threaded end segment 7 has a “go” gauge region 71, a “no go” gauge region 72, and a mid gauge region 73. A nut has to be threaded on the “go” gauge region 71, and cannot be threaded on the “no go” gauge region 72.
In addition, when the nut is threaded on the male threaded end segment 7 of the rotating shaft 8, an indicator (e.g., dial indicator) may be used to measure concentricity of a female thread in the nut. During measurement of the nut using the indicator, a plunger of the indicator is in contact with an end surface of the nut which is disposed to surround the rotating shaft 8. By rotating the rotating shaft 8, any irregularities in concentricity of the female thread of the nut will result in a displacement of the plunger.